This is a profoundly difficult issue and one that I truly hate to deal with. The situation as I see it is this:
A fertilized egg is a potential human. Conception, therefore is a clear and profound line that to reason has strong appeal. Once conceprion has occurred, we are talking about something that can become a humam is left to develope naturally. There is no getting this out of your mind im my opinion. It is a profoundly persuasive viewpoint. So next we have to ask, is human life of any importance. Well sometimes I delude myself into thinking mine is, and so I can't help but project onto a fertilized ova the same meaning that I attribute to myself. There is also, im my opinion, no escaping that conclusion. I no more want a fetus to die than I want to. If there is a God, than it is even more likely that every fetus is sacred. Even in non Christian Japan, when families have abortions they will go to a cemetary or some special shrines they have for this purpose to remember the fetus and acknowledge it and ask for forgivness for taking its life. Inwardly everybody feels, I think, that something about abortion is wrong.
On the other hand, humanity is divided into two sexes, only one of which bears children and only one of which will be forced to carry an unwanted child to term if it is illegal and she follows the law. For those of us who believe in evolution and random chance as part of the evolutionary process, it is just chance that there are two sexes and not one or three. There is a func=damental unjustice to the fact that only half of the people will be affected by banning abortion. Lots and lots of males will be telling females what to do when that wont apply to them. Very unjust indeed. So we have this accident that women bear children and that we reproduce by having sex. Nobody is conscious as a fetus. If any of us died as eight cells it would have been a totally unconscious death like the death of millions every time you drink. It's about on the same order as pulling out a hair. All that , of course depends on keeping your imagination out of it as is difficult to do like I suggested above. So we have conscious adults, the mother, who hav become pregnant and doesn't want to be. The fetus is on the one hand a sacred spark and on the other a hangnail, and carrying it to term will creat profround changes and difficulties, unwanted challenges, as opposed to pretty much the status quo if she aborts. It seems to me that caught between this logical vice that human life is sacred, and it's just a consequence of chance in action that we are forced to face this ethical issue in the first place, it seems to me that nobody can have a right to choose which way to go but the person who carries the child.
The trick is not to get into this situation, but reality is what it is. Once a choice has to be made, there isn't any choice that is all right or all wrong.